1. Technical Field
Embodiments of the present invention relate to a medium transporting state detecting device and a printing apparatus provided with the device.
2. Related Art
In a printing apparatus that is configured for transporting a sheet shaped medium (paper or film), a method for detecting medium displacement (transporting amount) by analyzing data of an image imaged on a sheet-shaped medium to be transported (also referred to as a “real image capturing method”) is known as disclosed in JP-A-2013-231658, for example.
In the real image capturing method of JP-A-2013-231658, it is problematic to increase a velocity of repeating the imaging. A more serious problem is increasing a transporting velocity. To solve these problems, one may consider widening an imaging area and capturing a high-definition image. However, this leads to the problem of increasing the size and the cost of an imaging device and an optical system device needed to acquire the image and increase the transporting velocity. In addition, even if a configuration in which the imaging area is widened and the definition of the captured image is increased can be achieved corresponds to an increase in the transporting velocity, it is necessary to further increase the size and the cost of the device. Further, there is a limit to widening the imaging area and to increasing the definition of the captured image. Therefore, further improvements are desired in devices for detecting a displacement of a sheet-shaped medium (paper or film).